Systems and methods for triaging software vulnerabilities

ABSTRACT

Systems and methods are provided for the classification of identified security vulnerabilities in software applications, and their triage based on automated decision-tree triage and/or machine learning. The disclosed system may generate a report listing detected potential vulnerability issues, and automatically determine whether the potential vulnerability issues are exploitable using automated triage policies containing decision trees or by extracting vulnerability features from the report and processing the extracted vulnerability features using machine learning models.

FIELD OF THE INVENTION

The present disclosure relates in general to the field of software security, and in particular methods and systems for scanning and remedying security vulnerabilities in software applications during their development.

BACKGROUND

During the development of software and applications, the procedure of scanning, analysis and remediation for security vulnerabilities are typically slow and manual. Basic techniques and tools in the art are known to scan and identify for vulnerabilities. However, experts are required to interpret the results, highlight the most relevant vulnerabilities, and suggest fixes. This usually takes a substantial amount of time, and such cybersecurity experts are in short supply. Software developers desire a faster process that can scale to meet demand, and maintain the quality of an expert analysis. Intelligence are desired to more efficiently and effectively scan software applications during their development stage.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages for embodiments of the present disclosure will be apparent from the following more particular description of the embodiments as illustrated in the accompanying drawings, in which reference characters refer to the same parts throughout the various views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the present disclosure.

FIG. 1 is a block diagram illustrating an example of an architecture for an exemplary system, in accordance with certain embodiments of the present disclosure.

FIG. 2 is a block diagram illustrating an embodiment of a scan engine and a vulnerability report engine for implementing the exemplary system depicted in FIG. 1 , in accordance with certain embodiments of the present disclosure.

FIG. 3 is a flow diagram illustrating an example of a method implemented by an exemplary extraction engine for implementing the system depicted in FIG. 1 , in accordance with certain embodiments of the present disclosure.

FIG. 4 is a block diagram illustrating an embodiment of a format engine and a vector engine for implementing the exemplary system depicted in FIG. 1 , in accordance with certain embodiments of the present disclosure.

FIG. 5 is a block diagram illustrating an embodiment of components for a vector engine, a classification engine and an output engine for implementing the exemplary system depicted in FIG. 1 , in accordance with certain embodiments of the present disclosure.

FIG. 6 is a block diagram illustrating an embodiment of components for various engines for implementing the exemplary system depicted in FIG. 1 , in accordance with certain embodiments of the present disclosure.

FIG. 7 is a chart illustrating examples of automated triage methods for implementing an exemplary system, in accordance with certain embodiments of the present disclosure.

FIGS. 8(a)-(b) are charts illustrating examples of scan results implemented by an exemplary system, in accordance with certain embodiments of the present disclosure.

FIG. 9 is a block diagram illustrating an example of a method implemented by an exemplary system, in accordance with certain embodiments of the present disclosure.

FIG. 10 is a flow diagram illustrating an example of a method implemented by an exemplary system, in accordance with certain embodiments of the present disclosure.

FIG. 11 illustrates an example automated triage policy (ATP) rule library and example steps for generating the ATPs and corresponding automated triage methods (ATMs) for the ATPs.

FIG. 12 shows an example mapping between ATPs and vulnerabilities.

FIG. 13 shows an example process for improved quality (IQ) guideline generation of FIG. 11 .

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

The present disclosure may be embodied in various forms, including a system, a method, a computer readable medium, or a platform-as-a-service (PaaS) product for scanning and rectifying security vulnerabilities in software applications. In some examples, a technical advantage of the disclosures described herein may include the identification of security vulnerabilities in software applications scanned during their development stage. Another technical advantage may be the reduction of false positives and duplicates in the scan results. Yet another technical advantage may be the analysis of vulnerability root causes. Another technical advantage may include providing additional information to human security analyst to reduce their scope of analysis to increase their efficiency. Technical advantages may include the classification of identified security vulnerabilities, and their automated triage based on machine learning. In certain examples, a technical advantage may include the translation or interpretation of the scan results to determine a remediation of the security vulnerabilities identified by the scan. In an example, a technical advantage may include the presentation of recommendations to software developers via a user interface or scan report in order to enable the secure development of a software application. Accordingly, an exemplary benefit of the present disclosures may include a reduction in time for security analysts to assess vulnerabilities, and an improved confidence in the security of the software application being developed. While inefficient technologies exist that provide security analysts with basic scan results that detect vulnerabilities, a technical advantage of the present disclosures may include an assessment of the scan results and a determination of actual vulnerabilities versus false positives.

FIG. 1 illustrates an embodiment of such a system 100 that may be implemented in many different ways, using various components and modules, including any combination of circuitry described herein, such as hardware, software, middleware, application program interfaces (APIs), and/or other components for implementing the features of the circuitry. The system 100 may include a scan engine 101, a vulnerability report engine 102, an extraction engine 103, a format engine 104, a vector engine 105, a classification engine 106, an output engine 107, a review engine 108, and/or a report engine 109. In an embodiment, the steps of the disclosed methods may be implemented by these engines 101-109.

In an embodiment, the system 100 may include a computing device 110, which may include a memory 111 and a processor 112. The system 100 may also include generated user interfaces (UIs) 113, and Representational State Transfer (REST) APIs 114 as shown in FIG. 2 , that may be adapted to enable communication between components, modules and databases. As discussed below, users may interface with the system 100 via the UIs 113. In some embodiments, the memory 111 may include the components and modules of the system 100, including the aforementioned engines 101-109, the UIs 113, and the REST APIs 114. The system 100 may also include a source code database 115, a vulnerability report database 116, a security vulnerability database 117, a java code repository or database 118, and/or a trained model database 119. Further, the system 100 may include a software-security server 120 and a router.

The computing device 110, the databases 115-119, the software-security server 120 and the router may be logically and physically organized in many different ways, in accordance with certain embodiments of the present disclosures. The databases 115-119 may be implemented with different types of data structures (such as linked lists, hash tables, or implicit storage mechanisms), and may include relational databases and/or object-relational databases. The databases 115-119 may be stored in the memory 111 of the device 110 and/or the software-security server 120, or they may distributed across multiple devices, servers, processing systems, or repositories. For example, the vulnerability report database 116 may be configured to communicate with the software-security server 120, and the vulnerability report engine 102 and the extraction engine 103 may be configured to communicate with the software-security server 120. In certain embodiments, the computing device 110 may include communication interfaces, display circuitry, and input/output (I/O) interface circuitry that may be controlled by the processor 112 in order to perform the process steps discussed below via the components and modules illustrated in FIG. 1 . As discussed below, users may interface with the system 100 via the UIs 113 displayed by the display circuitry.

FIG. 2 illustrates an embodiment of a scan engine 101 configured to scan source code 125 stored in a source code database 115. In an embodiment, the computing device 110 may include system circuitry that may implement any desired functionality of the system 100. As discussed below, in some embodiments, the scan engine 101 may be configured to scan source code 125 for security vulnerabilities 127. For example, the scan engine 101 may be implemented on an application-scanning client 128, as further discussed below, that may be configured to communicate with a source code database 115 that stores source code 125 to be scanned by the system 100. In an embodiment, the application-scanning client 128 may comprise a computing device 110. Alternatively, the source code database 115 may be implemented on the computing device 110, which may be configured to communicate with an application-scanning client 128 implemented on another device that may be adapted to communicate with a display 129. In some embodiment, as shown in FIG. 2 , the scan engine 101 may be further configured to generate vulnerability reports 130, and transmit the vulnerability reports 130 to the vulnerability report engine 102.

In certain embodiments, as an initial step of the disclosed methods, the scan engine 101 may receive a scan request to scan source code 125. In some embodiments, this may be the initial stage of the process where a client or user requests an analysis of source code 125 for the detection of security vulnerabilities or threats 127 within, or related to, the source code 125. In an example, this initial analysis may be performed by the system 100 in conjunction with a code analyzer 133. In certain embodiments, the code analyzer 133 in the scan engine 101 may be implemented by commercial packages or open source solutions. For example, the code analyzer 133 may include scanning tools such as Veracode, HCL App Scan, Checkmarx, and/or Fortify. Generally, the code analyzer 133 attempts to protect systems from security flaws in business-critical software applications through the use of vulnerability reports 130. The code analyzer 133 may scan source code 125 of a software product or application 135, and generate vulnerability reports 130. In certain embodiments, the vulnerability report engine 102 may generate vulnerability report 130.

In some embodiments, source code 125 for an application 135 that is selected, received and/or identified by a client 132 may be stored within the source code database 115. This may include the source code 125 that the client 132 requests to be assessed or analyzed in order to determine if the source code 125 includes security vulnerabilities 127 that could be deemed as exploitable by a security analyst. In an embodiment, the source code 125 may be pushed or transmitted to an application-scanning client 128. The application-scanning client 128 may include static application security testing software. In certain embodiments, a user or a client 132 may enter, input, submit or transmit source code 125 of a software application 135 to the application-scanning client 128.

The application-scanning client 128 may generate vulnerability reports 130 that correspond to the scan of source code 125. Typically, a security analyst may spend an extended period of time reviewing such a file via the application-scanning client 128 in order to determine source code 125 that may be a security vulnerability/threat 127, and to determine false positives that may be ignored. The vulnerability reports 130 may be stored in the software-security server 120. A vulnerability report 130 may include scan project code used by the code analyzer 133, which may include a suite of tools used by security professionals to scan enterprise software for security issues. In some embodiments, the vulnerability reports 130 may be stored in the vulnerability report database 116, which may include a relational database service (RDS). Vulnerability reports 130 that are stored in the vulnerability report database 116 may be transmitted to the software-security server 120. In an embodiment, the software-security server 120 may be configured to transmit the vulnerability reports 130 to the extraction engine 103 via a REST API 114, as denoted by the large arrow between the vulnerability report engine 102 and the extraction engine 103 shown in FIG. 2 .

FIG. 3 illustrates an embodiment of a feature extraction process implemented by the extraction engine 103, which may be configured to communicate with the software-security server 120. The feature extraction process of the disclosed methods may include the extraction of features 138 from vulnerability reports 130 that indicate whether a part of the source code 125 may be vulnerable or not based on the vulnerability reports 130 generated by the code analyzer 133, and the transmission of the features 138 to the format engine 104. This process may include the initial step of receiving (block 301) vulnerability reports 130 from the software-security server 120 via the REST API 114. Features 138 may be retrieved (block 302) that comprise different components of security vulnerabilities 127. In certain embodiments, such retrieved features 138 may identify the relevant threat of the security vulnerabilities 127 of the source code 125 based on the corresponding vulnerability reports 130.

The feature extraction process may also include the step of source code extraction. See block 303. This step may be performed by a source code extractor 300, as shown in FIG. 2 , which extracts original source code 125 from the application 135 that was scanned and/or tested. See block 303 in FIG. 3 . The extracted source code 125 may comprise the code 125 corresponding to the retrieved features 138. As such, the source code extractor 300 may be configured to communicate with the source code database 115, either directly or indirectly as shown in FIG. 2 . In addition, the process may include the step of pushing or transmitting (block 304 in FIG. 3 ) security vulnerabilities 127 of the extracted source code 125 to the vulnerabilities database 117. This transfer may be performed via the format engine 104. Accordingly, all of the security vulnerabilities 127 may be detected by the code analyzer 133 and the source code 125 may be transmitted to, and stored, in the vulnerabilities database 117 for further processing by the system 100.

In an embodiment, the format engine 104 may format the security vulnerabilities 127 received from the source code extractor 300 of the extraction engine 103 into a format configured to be received by the vulnerabilities database 117. In an example, the received security vulnerabilities 127 may be stored in a format compatible with, or usable by, the system 100. The format engine 104 may store all the security vulnerabilities 127 that were identified by the code analyzer 133, and received from the extraction engine 103, in a format adapted to enable conversion of the security vulnerabilities 127 by the system 100. The format may be readable by the system 100. In this format, the cleaned or reformatted vulnerabilities 127 may be analyzed via analytics experiments performed by the system 100. The cleaned vulnerabilities 127 stored in the vulnerabilities database 117 may be adapted for further conversion by the system 100. In certain embodiments, the vulnerabilities database 117 may be adapted to transmit the cleaned security vulnerabilities 127 to the vector engine 105.

FIG. 4 illustrates an example of a vector engine 105, and its interactions with the components of other engines 104 and 106 as denoted by the large arrows between the engines. The vector engine 105 may be configured to create feature vectors 173 for training machine learning (ML) models 141 in order to predict or determine if a security vulnerability 127 is actually a threat. The cleaned security vulnerabilities 127 may be converted from human readable features 138 into a format that can be processed by a machine learning model 141. In some embodiments, abstract syntax trees (AST) may be utilized as a method of breaking down the data for the cleaned security vulnerabilities 127 into a format that can be processed by a machine learning model 141. In an embodiment, as discussed below, the tokenizer 155 in the vectorising process may be substituted with ASTs 143. A syntax tree 143 may comprise a tree representation of the abstract syntactic structure of source code 125 written in a programming language. Each node of the tree 143 may denote a construct occurring in the source code 125.

As shown in FIG. 4 , an orchestrator 147 of a vector engine 105 may receive cleaned vulnerabilities 127 from the format engine 104. In some embodiments, the vulnerabilities database 117 may be configured to transfer cleaned security vulnerabilities 127 to the orchestrator 147 via an REST API 114. A vulnerability router 148 may be configured to communicate with the orchestrator 147. The vulnerability router 148 may scan the list of cleaned vulnerabilities 127, and classify each cleaned vulnerability 127 based on the type of security vulnerability 127 to which it corresponds. Based on the determined type of vulnerability 127 for a classified vulnerability 127, the classified vulnerability 127 may be routed in the system 100 based on predetermined machine learning rules or programming rules.

In certain embodiments, the vector engine 105 may include grammar files 151 that may define speech-to-text words, terms and phrases 152 which a grammar engine may recognize on a user device 110. Grammar files 151 may comprise .py, .java, .js, .cs, and/or .xml files. In an embodiment, the terms 152 listed in the grammar file 151 may be those for which the grammar engine searches and compares against verbal responses. When the grammar engine finds a matching term 152, the grammar engine may execute an associated command or enter the term 152 into a field. A lexical analyzer 154 may receive a grammar file 151 and vulnerability features 138, and perform tokenization via a tokenizer 155 in order to return features 138 in accordance with certain embodiments.

The tokenizer 155 may perform lexical analysis, lexing or tokenization. This may include the process of converting a sequence of characters 156 for the cleaned vulnerability 127 into a sequence of tokens 157. Tokenized vulnerability features 158 may include vulnerabilities 127 stored in memory 111 in tokenized format, which may comprise such a sequence of tokens 157. The repositories 160 may be selected where the targeted source code 125 may be hosted. In an embodiment, the repositories 160 may be selected based on their size. The hosted code 125 may be transmitted to a tokenizer 161, which may include a tool for language recognition. This tokenizer 161 may tokenize the repositories 160 and generate tokens 157.

In some embodiments, the vector engine 105 may include a FastText create model 162, which may include a library for learning of word embeddings and text classification. The FastText create model 162 may receive tokens 157 and generate a trained embedding model 166. The trained embeddings model 166 may include an embedding, which may include a mapping of a discrete, categorical variable to a vector of continuous numbers. In certain embodiments, each cleaned vulnerability 127 may be mapped to a vulnerability category 170 in order to generate a vulnerability ID 171 for each cleaned vulnerability 127 mapped to a category 170. In certain embodiments, a vectorizer 172 may receive the tokenized vulnerability features 158 as input, and may output a single feature vector 173. The feature vectors 173 may include all of the output collected from the vectorizer 172. Furthermore, a feature vector can include a link to a source code tree, where relevant source code can be obtained. These feature vectors 173 may be transmitted to the classification engine 106.

FIG. 5 illustrates an embodiment of a classification engine 106, and its interactions with the components of other engines 105 and 107, in accordance with certain embodiments of the disclosed systems 101. The feature vectors 173 may be utilized as input to the pre-trained ML model 141, predetermined programming rules 150 and/or blanket rules 174 in order to determine whether the cleaned vulnerability 127 is a threat or not. The classification engine 106 may determine whether a vulnerability 127 is a threat or not through at least three different methods: blanket rules 174, programming rules 150 and/or ML models 141. The blanket rules 174 and programming rules 150 may be applied to automated triaging methods configured to automate the triaging of the vulnerabilities 127. In certain embodiments, blanket rules 174 may be applied to vulnerabilities 127 routed through the vulnerability router 148, and the ML model 141 may not be required. Such a vulnerability 127 may be selected based on historical data that consistently indicates that the vulnerability 127 is exploitable. As such, it may be reasonable to automatically assume that the identified vulnerability 127 may be exploitable again. In some embodiments, programming rules 150 may be applied to the vulnerabilities 127 transmitted from the vulnerability router 148. The programming rules 150 may scan a vulnerability 127 in order to detect common patterns that have been identified as a threat. In an embodiment, an AST 143 may be processed by the system 100 but may be removed when converted. The classification engine 106 may also utilize machine learning. A vulnerability 127 may be processed by the system 100 (e.g., tokenized and vectorized) and the feature vectors 173 may be transmitted or inputted into the pre-trained model 141, which may have previously analyzed such feature vectors 173. As more vulnerabilities 127 may be converted into feature vectors 173, the system 100 may more often utilize the ML model 141 because the pre-trained model 141 may be more likely to have already determined whether the specific vulnerability 127 is exploitable. The exemplary classification engine 106 shown in FIG. 5 may determine whether a vulnerability 127 is a threat or not. The classification engine 106 may include a deterministic classifier 175, which may implement a classifying algorithm whose resulting behavior may be determined by its initial state and inputs. In an embodiment, the deterministic classifier 175 may not be random or stochastic. The classification engine 106 may also include a probabilistic classifier 179, which may include a classifier configured to predict a probability distribution over a set of classes. In an embodiment, the probabilistic classifier 179 may be based on an observation of an input, rather than only outputting the most likely class to which the observation may belong. In addition, the classification engine 106 may include a train classifier 184, which may be configured to be trained based on the feature vectors 173. In some embodiments, the train classifier 184 may be configured to train the deterministic classifier 175 and/or the probabilistic classifier 179. In certain embodiments, the train classifier 184 may be configured to train the trained model 141. Accordingly, the train classifier 184 may be adapted to communicate with the trained model 141, which may be included in the output engine 107. Rules (e.g., blanket rules 174) may be transferred to the deterministic classifier 175 as a set of rules. For example, blanket rules 174 may be implemented if the source code 125 is identifiable as being a threat based on historical data that consistently indicates that the vulnerability 127 is exploitable.

As shown in FIG. 4 and FIG. 5 , the vulnerability router 148 may either route the vulnerabilities 127 directly to the rule-based deterministic classifier 175 or the ML-based probabilistic classifier 179 via the vector engine 105. A set of vulnerability types may be associated with the rules 150 and 174. The vulnerability router 148 may determine a vulnerability type in the input vulnerability scan. When rules 150 or 174 associated with the determined vulnerability type are identified, the vulnerability router 148 may then route that input vulnerability scan to the deterministic classifier 175 for processing under the identified and pre-established rules. Otherwise, the vulnerability router 148 may route the input vulnerability scan to the probabilistic ML classifier 179. Example embodiments of triage methods for establishing the various rules 150 and 174 for various types of vulnerabilities are further discussed below in relation to FIG. 11 .

In some other embodiments, the vulnerabilities 127 may be routed to both the rule-based deterministic classifier 175 and the ML-based probabilistic classifier 179, and if the determination of whether the vulnerabilities 175 are exploitable are inconsistent between the deterministic classifier 175 and the ML-based probabilistic classifier 179, an additional arbitration may be performed to determine which classifier is more trustworthy.

An embodiment of the output engine 107 is also in FIG. 5 . The output from the output engine 107 may include initial findings received from the trained model 141 for the predictions of whether labelled vulnerabilities 187 are a threat or not. The trained model 141 may be stored in the trained model database 119. In some embodiments, the trained model 141 may be transmitted to the probabilistic classifier 179. The classification engine 106 may generate a list of labelled vulnerabilities 187, and/or predictions thereof, that may be stored and later reviewed by the system 100.

FIG. 6 illustrates an embodiment of the review engine 108, its interactions with the components of other engines 104-107 and 109, and exemplary processes implemented by the review engine 108. For example, the review engine 108 may be implemented to include a process for an output review (block 600) and a process for a vulnerability review and a model update (block 601). Through these processes, the review engine 108 may review the vulnerabilities 127 that the system 101 determined as being exploitable, and may use such vulnerabilities 127 to retrain the model 141 for future usage. This review may be transmitted back into the model 141 in order to further train the model 141.

The vulnerability review and model update process 601 may include the steps of updating vulnerabilities (block 602), retaining a model (block 603), and updating rules (block 604). This process may be configured to update the vulnerabilities database 117 with vulnerabilities 127 determined to be exploitable for the blanket rules 174. The updated vulnerabilities 127 may be transmitted back to the vulnerabilities database 117, which may store the cleaned vulnerabilities 127 in the format compatible with the system 100. In order to retrain the model 141, findings may be received from a security analyst (SA) review 606, a data scientist (DS) review 607, and/or a quality assurance (QA) review 608, and a data analysis 609 may be performed. Such findings received from the data analysis 609 may be transmitted to the orchestrator 147 of the vector engine 105. The findings may be utilized to update the blanket rules 174, the model 141 and the list of vulnerabilities 127.

The updated blanket rules 174 may include rules updated by the findings received from the reviews 606-608 and the data analysis 609. These reviews 606-608 may be performed by a data scientist and/or a security analyst. The data analysis 609 may be performed on new data in order to determine an optimal method for updating the blanket rules 174 and retraining the model 141. An automated triaging method instance 610 may be configure to automate the triaging of vulnerabilities 127. The vulnerability review and model update process 601 may be based on the combination of the review results 611 received from the security analyst review 606, the data scientist review 607, and/or the quality assurance review 608. The review results 611 may be transmitted to the report engine 109.

The report engine 109 may be configured to receive the review results 611 from the review engine 108. A full report may be generated that may include all the vulnerabilities 127 that are actually a threat, as analyzed by a quality assurance review 608. Quality Assurance Labelled Vulnerabilities 187 may be generated to include the vulnerabilities 127 that have passed through the system 100 and assessed by the Quality Assurance review 608. This review 608 may be performed by a quality assurance expert. A final report 147 may be generated for a client 132, and a HTML Report 188 may be generated to report all of the findings in a HTML format.

The final report 147 and the HTML Report 188 may be displayed via a device 110. The UIs 113 may be displayed locally using the display circuitry, or for remote visualization, e.g., as HTML, JavaScript, audio, and video output for a web browser that may be run on a local or remote machine. The UIs 113 and the I/O interface circuitry may include touch sensitive displays, voice or facial recognition inputs, buttons, switches, speakers and other user interface elements. Additional examples of the I/O interface circuitry includes microphones, video and still image cameras, headset and microphone input/output jacks, Universal Serial Bus (USB) connectors, memory card slots, and other types of inputs. The I/O interface circuitry may further include magnetic or optical media interfaces (e.g., a CDROM or DVD drive), serial and parallel bus interfaces, and keyboard and mouse interfaces.

In an embodiment, the components and modules for an exemplary system may compartmentalized into nine sections: Scan; Store Reports; Extract Features; Store all vulnerabilities in a canonical format; Create feature vectors, and/or abstract syntax trees; Classification; Initial Output; Review vulnerabilities; and, Final output plus Report generation. This listing of compartmentalized sections are not necessary in chronological order.

In an embodiment, the system 100 may include the steps of collecting and using different scan reports. These scan reports may be collected from multiple vendors. The scan reports may include the vulnerability reports 130 received from the code analyzer 133, in combination with reports from other vendors for various types of scans. The automated triaging may include a hybrid methodology. For example, the system 100 may use rules, filters, machine learning in conjunction with various feature vectors in combination. FIG. 7 illustrates examples of automated triage methods. Such methods may be trained and validated on various datasets for assessment purposes. FIGS. 8(a)-(b) illustrates examples of identified issue types and their corresponding percentage of total triage time, the highest remediation priority, and the automated triage method implemented.

In an embodiment, the system 100 may include integration of existing toolchains with custom annotated tags/variables so that automated-FPA files can be integrated back to existing toolchains. For example, the system 100 may be integrated with extract scan results from an application-scanning tool that may be implemented in memory 111 to automatically triage issues and push results back to the application-scanning tool. FIG. 9 illustrates such a system 100, in accordance with certain embodiments. In an embodiment, the system 100 may implement a vulnerability identification prioritization and remediation (ViPR) tool in the memory 111, which may include an integrated repository of data and analysis tools. The system 100 may include a frontend 191 and an API 114. The frontend 191 may communicate with an user, and, the API 114 may communicate with the software-security server 120. Further, the system 100 may combine and use information from scan reports of both Static application security testing (SAST) and Dynamic application security testing (DAST). The system 100 may combine SAST and DAST triage judgements to automatically propose remediation actions in a unified way, e.g. so that one fix may solve both a SAST and DAST issue.

The automated triage rules as shown in 150 and 174 of FIG. 5 used for the deterministic classifier 175 may be created for each of a predetermined set of types of vulnerabilities. An automated triage rule library may be established for the predetermined set of types of vulnerabilities. Such an automated rule library, for example, may include an automated triage policy (ATP) for each type of vulnerabilities, and may thus be referred to as an ATP rule library. Each ATP may further includes one or more automated methods (ATMs) in the form of various triage algorithms that may be invoked by the deterministic classifier 175 of FIG. 5 for assessing an input vulnerability. The assessment output of the deterministic classifier 175 may indicate whether the input vulnerability is not exploitable, exploitable, or that the exploitability is uncertain.

As such, the orchestrator 147 of FIG. 4 may first map an input vulnerability (e.g., a data frame from the vulnerability database 117 of FIG. 4 ) to either the deterministic classifier 175 or the ML probabilistic classifier 179 using the vulnerabilities router 148 of FIG. 5 . If the input vulnerability is mapped to the ML classifier 179, the feature vector creation process would be triggered, the feature vectors would be subsequently created for the input vulnerability, and the ML model would be loaded and invoked for processing the feature vectors to classify the input vulnerability. If the input vulnerability is mapped to the deterministic classifier 175, the classification engine 106 would further map this input vulnerability to one of the predetermined set of types of vulnerabilities and a corresponding ATP. The ATP and ATMs therein would be called from the ATP rule library and passed along with the data frame of the input vulnerability to the deterministic classifier 175 for classification of the input vulnerability.

An example ATP rule library is shown as 1102 in FIG. 11 . The ATP rule library 1102 may include a plurality of ATPs 1104, each for a type of the predetermined set of types of vulnerabilities. Each ATP 1104 may include a set of ATMs 1106. Each ATM, for example, may include one or more particular algorithms for deterministic vulnerability classification. As further shown in 1102 of FIG. 11 , the mapping of an input vulnerability to a particular ATP may be formed by the vulnerability mapper 1108. In some implementations, the vulnerability mapper 1108 may be part of the ATP rule library. An input vulnerability (e.g., a vulnerability data frame from the vulnerability database 117 of FIG. 4 ) may be passed to the ATP rule library 1102. The ATP rule library 1102 may output an ATP and pass the output ATP to the deterministic classifier 175, as shown by the arrow 1110 of FIG. 11 .

ATPs 1104 and ATMs 1106 for each of the predetermined set of types of vulnerabilities may be created in various manners and loaded into the ATP rule library 1102. The predetermined set of types of vulnerabilities may be established based on any methodologies. For example, the predetermined set of type of vulnerabilities may be based on Fortify vulnerability categories and types determined and defined via historical Fortify vulnerability scans and analysis. Each type of vulnerabilities may be associated with a vulnerability identifier (ID). An example for creating an ATP and ATMs for each of the predetermined set of types of vulnerabilities is shown in 1120 of FIG. 11 .

The ATP and ATM creation process 1120 may include a manual triage policy (MTP) generation process and an ATP/ATM generation process for each one of these types of vulnerabilities, as shown by 1122 and 1124 of FIG. 11 , respectively. As shown in 1122, the MTP may be specified as a definition of steps as part of improved quality (IQ) guidelines that security analysts (SAs) must take in order to triage (classify) the vulnerability as, for example, “not an issue”, “exploitable”, and “suspicious.” The MTP for a particular type of vulnerabilities, for example, may be represented by a list of questions that the SAs must check. The list of questions may be organized as a decision tree. In other words, the order in which the questions are asked is determined based on a decision tree. Specifically, what next question to ask in the list depends on the answer and output the previous question in the list. A list of questions and a decision tree may be created for each type of vulnerabilities. An example list of MTP questions for a “resource injection” type of vulnerability (example vulnerability ID of 0043) are shown below in Table 1.

TABLE I Question Not ID Question Yes No Sure 0043-1 Was the vulnerability found “Out of 0043-2 0043-2 on third party/open source Scope” libraries? 0043-2 Was the vulnerability found “Not an 0043-3 0043-3 on a test class, test directory, issue” or used for unit testing and assumed not deployed to production? 0043-3 Is the input coming from a “Not an 0043-4 0043-4 trusted source? issue” 0043-4 Is proper validation “Not an “Exploit- “Suspi- performed before the input issue” able” cious” data related to resources is used?

Table I above contains both the list of questions and the information about the decision tree for the list of questions. For example, when the answer to the first question in the list may be “out of scope” indicating that there is no issue with this particular vulnerability, the decision tree ends without proceeding further. However, if the answer to the question is a “No” or “Not Sure”, then the decision tree proceeds to the next question and question “0043-2” needs to be answered, as indicated in Table I. If the answer to question “0043-2” is “Not an Issue”, then the decision tree again ends. Otherwise, the decision tree proceeds to the next question and as specified in Table I, question “0043-3” needs to be answered next. This process proceeds as indicated in the example Table I until the decision tree ends. Table I thus prescribes a conditional sequence of triage steps. Each step poses a question for SAs to answer. The answer to a question decides a next step (either an end of the decision tree or a next question). Table I provides a path to reach a final triage decision.

FIG. 13 shows and example process of 1122 of FIG. 11 for generating the IQ guidelines that may be automated to form the ATPs and ATMs. The process 1122 may be used to process data sources including contextual data 1302, experimental data 1304, and computational data 1306 via an iterative validation (1310), enhancement (1312), encoding (1314), and aggregation (1316) procedure with an output being processed by the reaction module 1320 to generate the IQ guidelines stored in the database 1330. The IQ guidelines are used for the generation of ATPs and ATMs.

Returning to FIG. 11 , as further shown in 1124, once the MTP is created for each type of vulnerabilities, it may then be further determined what can be codified in the MTP to generate automated triage methods (ATMs) for the MTP. In particular, each of the questions in the MTP may correspond to a manual triage method (MTM) that may be converted and codified into an ATM containing automated algorithms (as shown by 1126 of FIG. 11 ). Each ATM may be codified in a function that may be called by the classification engine 106. An automated triage policy (ATP) corresponding to the MTP may identify the codified ATMs. An example is shown in Table II below.

TABLE II Step # Description ATM 1 Was the vulnerability found on ATM_isThirdParty_v1 third party/open source libraries? 2 Was the vulnerability found on a ATM_isTest-v1 test class, test directory, or used for unit testing and assumed not deployed to production? 3 Is the input coming from a ATM_PR_trusted_source_v1 trusted source? 4 Is proper validation performed ATM_PR_sanitisation_v1 before the input data related to resources is used?

In some embodiments, as shown by the vulnerability-ATP mapping in FIG. 12 , the ATP library includes multiple ATPs 1202. Each ATP may be associated with a unique identifier and represents a policy as described above. Each type of vulnerability may be associated with one of the ATPs (as shown by the mapping from 1204 to 1202 in FIG. 12 ) whereas each ATP may map to one or more types of vulnerabilities (as shown by the mapping from 1202 to 1204 in FIG. 12 , indicating that multiple different types of vulnerabilities may use a same ATP with a same decision tree 1206). Each ATP further encapsulates a decision tree as described above and links to one or more ATMs, as shown in 1206 of FIG. 12 . Each ATP thus may be embodied as an ordered container of ATMs, as shown in 1128 and 1106 of FIG. 11 . Each ATM corresponds to a step in the decision tree. ATMs are codified and may include various algorithms. An ATM as a callable function may be shared by different ATPs (as shown by the common “ATM_Third_Party” and “ATM_Is-Trust” functions between different ATPs in 1206 of FIG. 12 ). The ATMs thus may be collected in a unified function library or code repository. Each ATP, when referring to an ATM in a particular step in its decision tree, may identify the ATM by its unique function identifier in the function library or code repository, as shown in 1206 of FIG. 12 . Example codes of an ATP integrating a decision tree calling various ATMs are shown below:

def check(self, df): chain = self.strategy [‘chain’] if self.id == ‘ATP_ML’: item = chain[0] atm_config = item[‘config’] if ‘config’ in item else { } atm = item[‘class'](**atm_config) result_df = atm.check(df) return result_df else: cols = [‘vulnerabilityPrediction’, ‘vulnerabilityEngine’, ‘vulnerabilityDecisionTree’] result_df = pandas.DataFrame(columns = cols, index=df.index) # keep index [!!!] for i, row in df.iterrows( ): prediction = Labels.NS # default tree = [ ] lang = row[“programmingLang”] for item in chain: atm_config = item[‘config’] if ‘config’ in item else { } atm = item[‘class'](**atm_config) # ATM instance # check if the item in the chain has a lang attribute if “language” in item: if item[“language”] == lang: flag = atm.check(row) answer = ATP_Abstract.answer(flag) tree.append({ ‘name’: atm.atm_name, ‘output’: { ‘prediction’: item[answer] if answer in item else Labels.NEXT, ‘explanation’: atm.explanation, ‘confidence’: 0.5 } }) if answer in item: prediction = item[answer] break # prediction was found else: flag = atm.check(row) answer = ATP_Abstract.answer(flag) tree.append({ ‘name’: atm.atm_name, ‘output’: { ‘prediction’: item[answer] if answer in item else Labels.NEXT, ‘explanation’: atm.explanation, ‘confidence’: 0.5 } }) if answer in item: prediction = item[answer] break # prediction was found result_df.at[i, ‘vulnerabilityPrediction’] = prediction result_df.at[i, ‘vulnerabilityEngine’] = self.id result_df.at[i, ‘vulnerabilityDecisionTree’] = tree return result_df

In some embodiments, the output of the classification engine 106 of FIG. 5 above may include the input data frame with some additional columns. For example, one of the additional columns may include the prediction from the classification engine 106. Another additional column may include indication of the classifier (the deterministic classifier 175 or the ML probabilistic classifier 179) that is used for the prediction. Another additional column may include information indication the decision tree used in the deterministic classifier. The decision tree used may be identified by the ATP identifier.

The generation of the manual triage policy (MTP) or the decision tree for each of the predetermined set of types of vulnerabilities (1122 of FIG. 11 ) may be automated using a separate machine-learning model. For example, a machine learning model may be trained for selecting a list of questions from a question library in a particular order based on historical vulnerability prediction accuracy.

As shown in FIG. 9 , the method implemented by the system 100 may include the step of selecting projects via a user interface 113. See block 900. The frontend 191 may request projects (see block 901), and the API 114 may transmit such project requests to the software-security server 120. See block 902. As a result, the APO 114 may receive projects. See block 903. The frontend 191 may be adapted to display the received projects via the user interface 113. See block 904. In some embodiments, one of the displayed projects may be selected via the user interface 113. See block 905. In certain embodiments, the frontend 191 may be identify or determine the selected project. See block 906. The API 114 may be adapted to extract features for the selected project from the software-security server 120. See block 907. In an embodiment, the API 114 may be further adapted to: apply rules (block 908), apply filters (block 909), apply programmed filters (block 910), and/or apply machine learning models (block 911). In addition, the API 114 may be adapted to export results to the software-security server 120, in accordance with certain embodiments. See block 912.

In some embodiments, the communication interfaces may include wireless transmitters and receivers (herein, “transceivers”) and any antennas used by the transmit-and-receive circuitry of the transceivers. The transceivers and antennas may support WiFi network communications, for instance, under any version of IEEE 802.11, e.g., 802.11n or 802.11ac, or other wireless protocols such as Bluetooth, Wi-Fi, WLAN, cellular (4G, LTE/A). The communication interfaces may also include serial interfaces, such as universal serial bus (USB), serial ATA, IEEE 1394, lighting port, I²C, slimBus, or other serial interfaces. The communication interfaces may also include wireline transceivers to support wired communication protocols. The wireline transceivers may provide physical layer interfaces for any of a wide range of communication protocols, such as any type of Ethernet, Gigabit Ethernet, optical networking protocols, data over cable service interface specification (DOCSIS), digital subscriber line (DSL), Synchronous Optical Network (SONET), or other protocol.

The system circuitry may include any combination of hardware, software, firmware, APIs, and/or other circuitry. The system circuitry may be implemented, for example, with one or more systems on a chip (SoC), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), microprocessors, discrete analog and digital circuits, and other circuitry. The system circuitry may implement any desired functionality of the system 100. As just one example, the system circuitry may include one or more instruction processor 112 and memory 111. The memory 111 may store, for example, control instructions for executing the features of the system 100. In one implementation, the processor 112 may execute the control instructions to carry out any desired functionality for the system 100. Control parameters may provide and specify configuration and operating options for the control instructions and other functionality of the system 100. The system 100 may further include various databases or data sources, each of which may be accessed by the system 100 to obtain data for consideration during any one or more of the processes described herein.

In an embodiment, a method or system 100 for managing software may include the steps of scanning source code of a software product or application 135 to detect potential vulnerability issues, and generating an electronic document report listing detected potential vulnerability issues. The method/system may further include the steps of: extracting features from the electronic document report for each potential vulnerability issue; receiving policy data and business rules; comparing the extracted features relative to the policy data and business rules; and, determining a token based on the source code of a potential vulnerability issue. Further, the method/system may include the steps of: determining a vector based on the extracted features of a potential vulnerability issue and based on the token, and selecting one of a plurality of vulnerability-scoring methods based on the vector. In an embodiment, the vulnerability-scoring methods may be a machine learning modelling 141 method, a blanket-rules 174 automated triaging method, and/or a programming-rules 150 automated triaging method. In accordance with certain embodiments, the plurality of vulnerability-scoring methods may include any combination of such methods. The method/system may also include the steps of determining a vulnerability accuracy score based on the vector using the selected vulnerability-scoring method, and displaying the vulnerability accuracy score to a user. In an embodiment, the plurality of machine learning models may include random forest machine learning models.

In certain embodiments, as illustrated in FIG. 10 , a method or system 100 for managing software may include the steps of: obtaining an electronic document listing potential vulnerability issues of a software product (block 1000); extracting features from the electronic document for each potential vulnerability issue (block 1001); determining a vector based on the extracted features (block 1002); selecting one of a plurality of machine-learning modelling methods and automated-triaging methods based on the vector (block 1003); and determining a vulnerability accuracy score based on the vector using the selected method (block 1004). The method/system may further include the steps of scanning source code of the software product to detect the potential vulnerability issues, and generating the electronic document based on the detected potential vulnerability issues. Further, the method/system may include the steps of: receiving policy data or business rules; comparing the extracted features relative to the policy data or business rules; and, determining a token based on the scanned source code corresponding to at least one of the detected potential vulnerability issues. In some embodiments, the vector may be based on the token. The method/system may also include the step of displaying the vulnerability accuracy score to a user. In an embodiment, the machine learning modelling methods may include random forest machine learning models. In some embodiments, the automated-triaging methods may include blanket-rules automated triaging methods and/or programming-rules automated triaging methods. In certain embodiments, a method or system for accessing software vulnerability may include the steps of: accessing an automated triage rule library comprising a plurality of pre-defined automated triage policies corresponding to a plurality of predetermined vulnerability types, wherein each automated triage policy comprises a decision tree for determining whether one of the predetermined plurality of vulnerability types is exploitable; accessing a machine learning model library for probabilistic determination of whether one of the predetermined plurality of predetermined vulnerability types is exploitable; obtaining an electronic document listing potential vulnerability issues of a software product based on source code of the software product; determining whether the potential vulnerability issues are associated with one of the plurality of predetermined vulnerability types; and when it is determined that the potential vulnerability issues are associated with the one of the plurality of predetermined vulnerability types, determining whether the software product is exploitable based on processing the electronic document using an automated triage policy retrieved from the automated triage rule library associated with the one of the plurality of predetermined vulnerability types and a corresponding decision tree, otherwise determining probabilistically whether the software product is exploitable based on processing the electronic document using a machine learning model from the machine learning model library.

All of the discussion, regardless of the particular implementation described, is exemplary in nature, rather than limiting. For example, although selected aspects, features, or components of the implementations are depicted as being stored in memories, all or part of the system or systems may be stored on, distributed across, or read from other computer readable storage media, for example, secondary storage devices such as hard disks, flash memory drives, floppy disks, and CD-ROMs. Moreover, the various modules and screen display functionality is but one example of such functionality and any other configurations encompassing similar functionality are possible.

The respective logic, software or instructions for implementing the processes, methods and/or techniques discussed above may be provided on computer readable storage media. The functions, acts or tasks illustrated in the figures or described herein may be executed in response to one or more sets of logic or instructions stored in or on computer readable media. The functions, acts or tasks are independent of the particular type of instructions set, storage media, processor or processing strategy and may be performed by software, hardware, integrated circuits, firmware, micro code and the like, operating alone or in combination. Likewise, processing strategies may include multiprocessing, multitasking, parallel processing and the like. In one embodiment, the instructions are stored on a removable media device for reading by local or remote systems. In other embodiments, the logic or instructions are stored in a remote location for transfer through a computer network or over telephone lines. In yet other embodiments, the logic or instructions are stored within a given computer, central processing unit (“CPU”), graphics processing unit (“GPU”), or system.

While the present disclosure has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure. Although some of the drawings illustrate a number of operations in a particular order, operations that are not order-dependent may be reordered and other operations may be combined or broken out. While some reordering or other groupings are specifically mentioned, others will be apparent to those of ordinary skill in the art and so do not present an exhaustive list of alternatives. 

What is claimed is:
 1. A system for assessing software vulnerability, comprising: a memory to store executable instructions; and a processor adapted to access the memory, the processor further adapted to execute the executable instructions stored in the memory to: access an automated triage rule library comprising a plurality of pre-defined automated triage policies corresponding to a plurality of predetermined vulnerability types, wherein each automated triage policy comprises a decision tree for determining whether one of the plurality of predetermined vulnerability types is exploitable; access a machine learning model library for probabilistic determination of whether one of the plurality of predetermined vulnerability types is exploitable; obtain an electronic document listing potential vulnerability issues of a software product based on scanning source code of the software product; determine whether the potential vulnerability issues are associated with one of the plurality of predetermined vulnerability types; when it is determined that the potential vulnerability issues are associated with the one of the plurality of predetermined vulnerability types: classify whether the software product is exploitable among classes of being exploitable, not exploitable, or suspicious of exploitability based on a rule-based deterministic classifier for processing the electronic document using an automated triage policy retrieved from the automated triage rule library associated with the one of the plurality of predetermined vulnerability types and based on a corresponding decision tree; determine probabilistically whether the software product is exploitable based on a pretrained machine-learning probabilistic classifier; and use an arbitrator to determine which classifier is more trustworthy when there is a classification conflict; and otherwise, when it is determined that the potential vulnerability issues are not associated with the one of the plurality of predetermined vulnerability types, only determine probabilistically whether the software product is exploitable based on the pretrained machine-learning probabilistic classifier.
 2. The system of claim 1, wherein the decision tree comprises a set of progressively ordered automated triage methods.
 3. The system of claim 2, wherein each automated triage method in the automated triage policy is configured to generate a triage output when processing the electronic document.
 4. The system of claim 1, wherein the processor is adapted to determine whether the software product is exploitable based on the automated triage policy by invoking the automated triage methods of the automated triage policy progressively according to the decision tree when output of the automated triage methods indicates that the software product is exploitable or that the exploitability of the software product is undetermined, and by terminating the decision tree when an triage output of unexploitable is obtained.
 5. The system of claim 3, wherein each automated triage method of the automated triage policy comprises a codified version of one or more triage algorithms for determining a triage output as an answer to a predetermined triage inquiry among a predetermined inquiry tree of the automated triage policy.
 6. The system of claim 5, wherein each triage policy and the automated triage methods are established based on a set of guidelines derived based on separate contextual data, experiential data, and computational data.
 7. The system of claim 6, wherein the set of guidelines are encoded in a predefined format that is processed to generate the codified version of the one or more triage algorithms.
 8. The system of claim 1, wherein the processor is further adapted to: scan the source code of the software product to detect the potential vulnerability issues; and generate the electronic document based on the detected potential vulnerability issues.
 9. The system of claim 8, wherein the processor is adapted to determine probabilistically whether the software product is exploitable by: extracting features from the electronic document for each potential vulnerability issue; determining a vector based on the extracted features; selecting one of a plurality of vulnerability-scoring models based on the vector, the vulnerability-scoring models selected from the machine learning model library; and determining a vulnerability accuracy score based on the vector using the selected one of the vulnerability-scoring models.
 10. The system of claim 9, wherein the processor is further adapted to: receive a set of policy data or business rules; compare the extracted features relative to the set of policy data or business rules; and, determine a token based on the scanned source code corresponding to at least one of the detected potential vulnerability issues.
 11. The system of claim 10, wherein the vector is based on the token.
 12. The system of claim 9, wherein the processor is further adapted to display the vulnerability accuracy score to a user.
 13. The system of claim 1, wherein the machine learning model library comprises a plurality of random forest machine learning models.
 14. A method for assessing software vulnerability, comprising the steps of: accessing an automated triage rule library comprising a plurality of predefined automated triage policies corresponding to a plurality of predetermined vulnerability types, wherein each automated triage policy comprises a decision tree for determining whether one of the plurality of predetermined vulnerability types is exploitable; accessing a machine learning model library for probabilistic determination of whether one of the plurality of predetermined vulnerability types is exploitable; obtaining an electronic document listing potential vulnerability issues of a software product based on scanning source code of the software product; determining whether the potential vulnerability issues are associated with one of the plurality of predetermined vulnerability types; when it is determined that the potential vulnerability issues are associated with the one of the plurality of predetermined vulnerability types: classifying whether the software product is exploitable among classes of being exploitable, not exploitable, or suspicious of exploitability based on a rule-based deterministic classifier for processing the electronic document using an automated triage policy retrieved from the automated triage rule library associated with the one of the plurality of predetermined vulnerability types and based on a corresponding decision tree; determining probabilistically whether the software product is exploitable based on a pretrained machine-learning probabilistic classifier; and using an arbitrator to determine which classifier is more trustworthy when there is a classification conflict; and otherwise, when it is determined that the potential vulnerability issues are not associated with the one of the plurality of predetermined vulnerability types, only determining probabilistically whether the software product is exploitable based on the pretrained machine-learning probabilistic classifier.
 15. The method of claim 14, wherein the decision tree comprises a set of progressively ordered automated triage methods.
 16. The method of claim 15, wherein each automated triage method in the automated triage policy is configured to generate a triage output when processing the electronic document.
 17. The method of claim 14, wherein determining whether the software product is exploitable based on the automated triage policy comprises: invoking the automated triage methods of the automated triage policy progressively according to the decision tree when output of the automated triage methods indicates that the software product is exploitable or that the exploitability of the software product is undetermined; and terminating the decision tree when a triage output of unexploitable is obtained.
 18. The method of claim 16, wherein each automated triage method of the automated triage policy comprises a codified version of one or more triage algorithms for determining a triage output as an answer to a predetermined triage inquiry among a predetermined inquiry tree of the automated triage policy.
 19. The method of claim 14, wherein determining probabilistically whether the software product is exploitable comprises: extracting features from the electronic document for each potential vulnerability issue; determining a vector based on the extracted features; selecting one of a plurality of vulnerability-scoring models based on the vector, the vulnerability-scoring models selected from the machine learning model library; and determining a vulnerability accuracy score based on the vector using the selected one of the vulnerability-scoring models.
 20. A non-transitory computer-readable medium including instructions configured to be executed by a processor, wherein the executed instructions are adapted to cause the processor to: access an automated triage rule library comprising a plurality of pre-defined automated triage policies corresponding to a plurality of predetermined vulnerability types, wherein each automated triage policy comprises a decision tree for determining whether one of the plurality of predetermined vulnerability types is exploitable; access a machine learning model library for probabilistic determination of whether one of the plurality of predetermined vulnerability types is exploitable; obtain an electronic document listing potential vulnerability issues of a software product based on scanning source code of the software product; determine whether the potential vulnerability issues are associated with one of the plurality of predetermined vulnerability types; when it is determined that the potential vulnerability issues are associated with the one of the plurality of predetermined vulnerability types: classify whether the software product is exploitable among classes of being exploitable, not exploitable, or suspicious of exploitability based on processing the electronic document using an automated triage policy retrieved from the automated triage rule library associated with the one of the plurality of predetermined vulnerability types based on a corresponding decision tree; determine probabilistically whether the software product is exploitable based on a pretrained machine-learning probabilistic classifier; and use an arbitrator to determine which classifier is more trustworthy when there is a classification conflict; and otherwise, when it is determined that the potential vulnerability issues are not associated with the one of the plurality of predetermined vulnerability types, only determine probabilistically whether the software product is exploitable based on the pretrained machine-learning probabilistic classifier. 